1. Field of the Invention
The invention relates to an electronic circuit and a signal processing method thereof and particularly relates to a transmission circuit adapted for an input and output (I/O) interface and a signal transmission method thereof.
2. Description of Related Art
Generally speaking, a link needs to be established between two electronic devices according to the standard of the transmission interfaces thereof in order to perform signal transmission between the two electronic devices. Once the link is successfully established, signal transmission between the electronic devices can be carried out. Nevertheless, when signals are transmitted at high speed, the signal strength may be improperly deteriorated due to a low-quality transmission channel between the electronic devices. In that case, the bit error ratio may be raised due to the deteriorated signal strength or the increased noise jitter, which affects communication quality. Thus, the quality of the transmission channel may significantly affect the communication quality between electronic devices.
According to the conventional technology, an equalizer circuit is often disposed in the transmission circuit for the I/O interface of the electronic devices for equalizing the received input signals. However, conventional equalizer circuit usually performs the equalizing operation with fixed preset parameters. That is to say, regardless of the quality of the transmission channel, the parameters preset in the equalizer circuit cannot be adjusted according to different transmission channel characteristics. As a consequence, in the application of some transmission interface standards, the equalizer circuit may not cooperate with low-quality transmission channels and may provide incorrect signals to back-end circuits and cause erroneous decoding. For the above reasons, how to adjust the equalizing operation parameters of the equalizer circuit according to transmission channels with different qualities has become an important issue.